Viessmann Vitocrossal 200 CM2 186 Service Instruction page 52

Troubleshooting
Fault Codes
(continued)
Displayed System Characteristics
Fault Code
F F4 Poor start-up characteristics,
rotary damper does not close,
solenoid valve does not switch
F F4 No flame builds during safety
time; ionization flame monitor
reports no signal
F F4 No flame builds during safety
time; ionization flame monitor
reports no signal
F F4 No flame builds during safety
time; ionization flame monitor
reports no signal
F F5 Air pressure switch 1 shows
no air pressure, fan does not
operate acA
F F5 Air pressure switch 1 switches
off during operation
F F6 Gas pressure switch shows no
gas pressure
F F7 Fan pressure is created during
the idle state check of air
pressure switch 1
F F7 Contact of air pressure switch
1 not closed in idle state
F F8 Flame extinguishes during
operation
F F8 Flame extinguishes during
operation
F F8 Flame extinguishes during
operation
F F9 Fan not running; fan speed not
reached
F F9 Status duration too long, fan
ramp-up
52
Cause
Servomotor faulty, servomotor
connecting cable faulty, solenoid
valve faulty, burner control unit
output relay faulty
Incorrect gas type selected
Gas valve does not open
Combustion characteristics not
ideal
Air pressure switch 1 faulty,
incorrectly connected or
incorrectly set
Flue gas back pressure;
condensate built up; air pressure
switch 1 hose faulty; connecting
hose leaking
Gas shut-off valve closed; gas
pressure switch faulty; multiple
problems with gas supply
Wind influence on fan
Air pressure switch 1 faulty
Incorrect gas type selected
Burner gauze assembly faulty
Combustion characteristics not
ideal
Fan faulty; cables are faulty or
broken
Internal fault; fan cannot reach
its set value
Vitocrossal 200 CM2 186 to 311 Service
Measures
Replace connecting cable; replace
servomotor; replace solenoid
valve; replace burner control unit
Adjust gas type (see page 9)
Check the connecting cable;
check the gas valve and replace
if required
Adjust the burner (see from page
15, if necessary, also adjust the
setting screws when the burner is
OFF to be able to start the burner)
Replace air pressure switch 1,
connect or set correctly
Remove flue gas back pressure;
check if condensate banked up;
reset burner control unit; replace
hose
Open gas shut-off valve; check
gas flow pressure; replace gas
filter if required; reset burner
control unit; replace gas valve
Check flue outlet or (chimney)
Replace air pressure switch 1
Adjust gas type (see page 9)
Check burner gauze assembly;
replace if damaged
Adjust burner (see from page 15)
Check cables; replace fan if
required
Replace fan or burner control unit